A few basics. The name in the talent file, not the name of the talent file, must exactly match the name in the .car file (the filename itself is irrelevant). There must not be two talent files with the same name in them (all too easily overlooked when hundreds of cars are installed). This is complicated by the fact the game will read talent files anywhere in the install folder, they could be in the sound folder or locations folder, makes no difference; all the subfolders for talent are just to organize for us poor humans. The .car files should have a "ComparativeTime=", this is usually set between 101-110 and helps adjust qual times if the AI do not run/complete qualifying. And I recommend Tom's Driver Shop and Tom's Talent Scout, they help with all of this (the latter will find duplicate names).
Then you need to adjust the track AIW files; this is usually the issue if AI speeds vary greatly from practice to qualify to race - you are five seconds/lap faster in practice then they leave you in the dust at the start of the race, or vice versa. Run enough laps at the track to know your times, now set "midadjust", qualratio", and "raceratio" to 1.000 in the AIW file, and set AI strength in the game menu to 100 (you will now be seeing the AI run each stage at the base speed of the track). Let the AI run practice laps for a few minutes (accelerate time if you wish) and note their speeds, tweak "midadjust" to set their times where you want them (this works like a percentage, 1.100 would be roughly 10% faster, 0.900 roughly 10% slower). Now let the AI run qualifying sessions and tweak "qualratio" to adjust their times, then let them race and adjust "raceratio" for their race times. Note that you must tweak "midadjust" first as it affects both race and qual speeds, the latter two do not affect each other or "midadjust" so can be further tweaked at any time. The more AI cars you use the better results you will get since there are not only talent file variations but a basic random factor applied by the game. (I have a "test" series of 12 identical cars and talent files for such tweaking, and there are still minor variations.) When you now adjust the AI Strength in the menu all times will track equally. You will probably want to tweak the talent files again once the tracks are done.
But, the track is now adjusted for this type car, go there with a greatly different type of car and you will notice the settings no longer optimum. I keep a text file in each track folder with these settings for different mods ...and try to remember to copy/paste before racing, lol. Not as bad as it sounds, basically settings for modern F1, vintage F1, GT, etc.
(FWIW, this also applies to GTL and rfactor; though rfactor does not have "raceratio" and "qualratio", you use "midajust" for practice and race, and set qual solely from the talent files.)